Gear cutter



E. c. HEAD 1,913,486

GEAR CUTTER June 1 3, 1933.

' 4 Sheets-Sheet 1 Filed June 8, 1929 HEB-Mil @im unnuluwnupuunnnmmmgINVENTOR 5547662 C {7921 June 1933. E. c. HEAD 1,913,486

GEAR CUTTER Filed June 8, 1929 4 Sheets-Sheet 2 0 61 Alllllllllll JO 8 zIA a:

'4 'INVENTOR his \ATTORNE Jime 13, 1933. E. c. HEAD 1,913,436

GEAR CUTTER Filed June 8, 1929 4 Sheets-Sheet s E j a 1m mu z 73 1 5 170169 W INVENTOR 16,0 fig Z 17641 I i L, v hSATTQRNEYj June 13, 1933. E,c. HEAD 1,913,486

GEAR CUTTER Filed June 8. 1929 4 Sheets-Sheet 4 Zz's ATTORNEY/7WL/ 7 "3ocutter constructed according Patented June 13, 1233 UNITED STATE J ATENT OFFICE v nnunsr 0.

HEAD Fnocnnsrnn, NEW Yonx; nssreuon To GLEASON wag-"K510? H E N YORK-AcCORPORATIO N ounnw YORK Application filed June s, 1929'. SerialIra-369,289.

" The present invention relatestogear cut ters andparticularly to gearcutters of the face mill type such as are used in the cuttmg of spiralbevel and hypoid gears.

The present invention hasfor its primary purpose to make it .possibletoobtain an ex- 7 tremely accurate cutter. Other ob ects of the inventionaretoprovide va construction which sgconvenlent for adjustment and .10which permits the blades to betrued up on thecutter head quickly. Stillother obJects of the invention :Wlll be apparent hereinafter V mentofthe invention;

, Figure 2 1s a section on: theline22 of Figure 1;

Figure 3 is a plan view of a modified form ofcutter; v V v 7 Figured isa section'through this cutter taken on the line HOfFigure 3; Figure '5is a sectional view on an enlarged scale taken onthe line 5-5 of Figure3; v 'Figure 6 is a fragmentary'plan view of a to anothermodification of this invention; Figure '7 is a se ,tional view taken onthe line'77 of Figure 6; 1 Figure 8 is afragmentary plan .view of stillanother modificationjof this invention;

' Figure 9 is a section taken on the line.99 of Figure 8; f I H jFigure, 10 is a fragmentaryi sectional view taken radially of avcutterconstructed according :to a further modification of this invention;

, Figure 11 is asectional view of the same cutter taken at right anglesto Figure 10 Figure 12 is-a fragmentary plan view ofa cutter constructedaccording to another modification ofthis invention; a, a

Figure 13 is a section through this cutter taken on the line 13-13 ofFigure 12.;

' Figure 14 is a section taken on the line 1414of Figure 12;

; Figure 15 is a section on the line15l-15of Figure 17;

Figure 16 is alfragmentary plan View of a cutter constructed accordingto'a still furthermodification of this invention;-

Figure 17 is a sectional view ofthis cutter taken on the line 17-17 ofFigure16; j

Figure 18 isa corresponding sectional View taken radially oii'a' cutterconstructed a'ccording to a still further modification of thisinvention; I r, r I Figure 19 is a fragmentary. plan view of a cutterconstructed according to another embodiment of this invention; Figure 20is a sectional View on an enlarged scale taken on the line 202O ofFigure 19;

Figure 21 is a section on the line 21 -21 of Figure 19;

"Figure 22 IS? a fragmentary sectional view of a still furthermodification of this invention; I I v. I

- Figure 23 is a" sectional view on. an en.-

larged scale taken on the line 23-23. of

Fi ure 22.; and r V g igure 24, is a. section taken on the line 175',24245 .of Figure 22; v

I Referring first tothe form shownin ures '1 and 2, 30 designates thecutter head.

This head is provided with a plurality of equi-spaced radial slots inwhich are adjust- 30 I} ably mounted the blocks 31 which serve to 'carrythe cutting blades 32. The blades 32 have acutting portion 33 and a bodyportion 34. The cutting portion 33 extends beyond the blocks 31 and theadjacent sideface of the 35 cutter head in the direction of the axis ofthe cutter head; The cutting portions 33 are formed in the usual or anysuitable manner being relieved at the tip and on the sides back 7 of thecutting edge or edges. r In the: drawings; all of the blades 32 areinside blades, that is, areprOvided with inside cutting edges.

It is to b'eounderstood; however, thatalternate blades might be providedwithvoutside cutting edges or each blade might be formed so as to haveboth inside and outside cutting j I edges, 1 a I ,7 The body portion 34of the blade is in the form of a cylindrical stud integral with thecut-tingportion 33, and is ofreducedsiz'e to 0" provide a shoulder 35between the cutting portion 33 and the stud 3 1. The shoulder 35 ispreferably made circular in shape and fits into a correspondingly shapedrecess formed in the upper face of the block 31 while the stud 34 passesthrough a hole formed in the block. Each blade 33 is held in position inits block by a nut 36 that threadsonto the lower end of the stud 34 andserves to draw the shoulder 35 down firmly into its recess in the block31.

The blade 32 is very simple to make and because of the shape of the stud3 1 and shoulder 35 can be adjusted angularly on its block 31 to permitusing the cutter in an intermittent indexing process as is the cutter ofthe patent to James E. Gleason, No. 1,236,834 of August 14, 1917,0r in acontinuous indexing process, as is' the cutter of the patent to James E.Gleason No. 1,219,378 of December 11, 1917.

Theblocks 31 may be adjusted radially on the cutter head by means ofscrews 10, only one of which is shown in Figure 1. These screws 410thread into the cutter head alongside of the blocks 31 and'the heads 41of the screws engage in kerfs or recesses 42 formed in the sides of theblocks 31. As shown in Figure 1, it is preferable to provide each block.31 with two kerfs or recesses 12 so as to permit interchangeablemanufacture and enable each block 31 to carry either an outside or aninside cutting blade. The blocks 31 are secured in any adjusted positionby means of the bolts 13, and washers 44:, the stems of the boltspassing through slots 15 formed in the blocks 31 and threading into thecutter head and the heads of the bolts'beingreceivedin countersunk slots46 formed in the blocks 31.

The cutter head 30 can be secured to the cutter spindle 48 by means of abolt 19.

Theblades of face mill gear cutter are'relieved on grinding machinesbuilt especially .for that purpose and the greatest care is eXercised toinsure that the proper pressure angle will be ground on the relievedblades. Difficuity is sometimes experienced, however, in setting up theblades in the cutter head in positioning the blades so that the correctpressure angle will be maintained in the assembled cutter. Figures 3 to5 represent a form of this invention which is preferred over that shownin Figures 1 and 2 because it eliminates substantially all possibilitiesof error creeping in in the setting or adjustment of the cutting bladesin the cutter head. It is compara tively easy to grind fiat surfaces sothat they match each other'and in the form. of the invention shown inFigures 3 to 5 inclusive, advantage is taken of this; The cutter head isground so that one of its side faces is flat and the blade is so shapedand ground that it has a flat base surface adapted to rest against theflat side face of the head with the consequence that a cutting bladewhich has been ground to a predetermined pressure angle on therelievadjustment on the cutter ing grinder will not betilted whenpositioned on the cutter head and the finished cutter will have the truepressure angle.

The cutter head 50 which may be provided with a peripheral ring orshoulder 51 has one side face 52 ground absolutely plane or flat. Aplurality of radial grooves 53 are formed in this side face of thecutter head and radial slots 54 are cut transversely through the head tocommunicate with the grooves 53. The cutter blades 55 have a cuttingportion 56 and a foptor supporting portion 5'? integral therewit Thecutting portions of the blades may be of any usual or suitableconstruction. The cutter shown in Figures 3 to '5 inclusive is of theface mill hobbingtype and'the blades are formed according to theprinciples described in Patent N 0. 1,249,378 above mentioned. Theblades 55 shown are adapted to cut alternately on opposite sides of theteeth.

The bottom or inside face 58 of the supporting portion 57 of each bladeis ground so as to provide an absolutely plane or flat sur-- faceadaptedto rest on the plane side face '52 of the cutter head and thissupporting portion 57 is formed with a tongue 59 which is adapt ed toengage in the grooves 53 formed in the cutter head to guide the blade 55inits radial head. i

Inthe form shown in FiguresS to 5 inclusive, the blades are adjusted byscrews 60 which are provided with heads 61' that engage in kerfs orrecesses formed in the undersides of the tongues 59 of the blades andwhich thread each into another screw 62 which in turn threads into thering 51; of the cutter head. The screw60 is made with a different numberof threads per inch from that of thescrew 62. In one constructiona'tually used the s'crew'GO'had twenty threads per inch and thescrew 62iiineteentlireads per inch. As the screw 60 is heldffrorn turnin'g'bythe head 61',' one turn ofthescrew 62 will impart a movement to theblade 55. equal to the difference in the amount oflead ofltlie twoscrews. Thus, the two screws 60 ,62form a differential screw deviceenabling a very accurate adjustment of the cutter bladesto be made. Eachof the bladesis seemed in an adjusted position by means of bolts 64which thread into the foot portions 57 of the blades findlipass throughthe slots 54 in the cutter ground flat and the inside face of the bladesalso ground flat, the blades will seat accurately on the cutter head andwill not tilt when being secured thereto 'or adjusted thereon.

As the blades are accurately ground inth'e With the sideface 520fthecutter head against a fiat surface on the cutter head is alsoutilized. The difference between the modification shown in Figures6 and7 and that shown inFigures 3 tot inclusive is in the 5 means foradjusting the cutter blade in the cutter head. I.

In Figures 6 and 7, the cutter head is. indicatedat 7 0.. Its side face71 is ground plane and. is iorinedwith'radial grooves 7 2. Radial slots7 3 are :cut throughthe cutter head and communicate with the grooves 72.The blades 7 4 have their. cutting'jportions 75 formed in any usual orsuitable manner and their foot .or supporting. portions76 areprovidedwith inside faces whichareiground fiat to rest on the side face71 of the'cutter head and are provided with tongues adapted to engage inthe grooves 720i the cutterhead. This construction is the sameas in themodification of sive, The supporting portions 76 have a stud 77 formedintegral there-withand adapted to extendthroughthe slot.7 3 formed inthe cutter head. Each of the blades 74 is adjusted radially onthe-cutterhead 7 0 by means of a screw 7 Swhich threads through a nut 7 9 Ysecured to the cutterhead and into the stud 77 ofthe blade. The blade issecured in any adjusted position by means of the washer 80 and thenut.81which threads onto the "stud 77 of the blade.- I g In themodification; illustrated in Figures 8 and 9, the principle of-afiatsurface on the blade resting against aplaneside face on the head isagain used. Here the cutter head is designated-at I It is again providedwith a plurality of radial grooves 86-and.

with transverse slots 87'communicatingwith these Jgrooves. i-The cutterblades',-.of which .only one is shown, have cutting portions 88 andsupporting portions 89. The supportingv 'portions'89pas inthe. caseofthe. blades il- -lustrated in Figures-3 to 5. inclusive, have planeinside faces adapted torest on the plane side face 90: of thecutter headand have stongues adapted toengage in the grooves .86 of the cutter headto guide the blades 'in -their radial adjustments on: the cutter head;Each of'the blades is provided with anintegral stud 91- which is adaptedto extend through a slot-'87: of the cutter head; Each blade canbe-adjusted in the cutterhead 85 byfmeans of the-screws 92;and 93 whichengage opposite sides of the stud 91'. V The screw v93 is heldiagainstrotation by means -of .a pin94 that engages in a slot 95cutlongitudinally; in thev screw and, the screw threadsinto a nut 96that is held between the side walls of arecess 970L113 into the cutter160 head inalignment'with the radial groove 86.

.Each blade is held'in any adjusted. position by meansqof thewasher9.81and thenut 9.9 that threads onto the stud 91 of the blade. Figures10 and 11 show a further modifica- 1 .tion of theinvention Qmployingitheprinciple.

the invention shownin-Fig'uresB to 5. inclu-.

manner of Patent No. '1,236,83 i-above-.re-

tionand whether the blades have one or two i.

face 121 of-the cutter head-andisrformed of a fiat surface on the bladeresting against a flat side face ofthe cutter head. ;;100[designates thecutterhead. Its, side facei 101 .is ground plane. and is formedwith aplua ralityofradialgrooves 102. Radialslots 103 are cuttransverselythrough-thecutter head in alignmentwith the. grooves 102. Only one ofthecutting blades is shown. 104' designates the cutting portion of thisblade and 105. thefoot. or supporting portion. The foot portion105hasits insideface .106 ground. plane to reston the side face 101 of the.cutter head and is formed with a: tongue 107. which is adapted toiengagein a'radial groove 102 of the cutter-head to .%guide the blade in itsend with a knurled head 111 whichis receivedi into aslot or 'recess 112formed, in the cutter head; Each blade is heldin any. adjustedposition'by means of a washer 113 and aunt 114 that threads on to thestud Figures 12 to 14 inclusive illustrate a fur.- ther modification ofthis invention in which it the principle of a flat surface onthebladeengagingja flat sideface of the cutter head is. utilized.designates the cutter head,- It is providedwith aplane side'face 121 andthis. side face isfformed at equi-spaced intervals with radial grooves122 while .radial slots 123 are cut through .the'cutter head bladesareformed with cutting portions 125 and with foot'or supporting portions:126.

fInthe' cutter shown, the cutting portions are allfarranged on acircleaccording to-.;the

ferred to and the blades are-alloutside cutting blades, eachblade havingan outside cutting edge. It is to be understood throughout thisspecification that the invention is independent of the form of thecuttingportion and that each modification isfapplicable. whether thecutter-be constructed for employment'in an'i'ntermittent indexingoperatlon or 1I1'L.COI1131I111011S lndexing operacutting edges andwhether that one cutting edge be an inside or an outside cutting edge.

1 The supporting portion .126 ofeach blade has its inside face planeto-rnatchpthe side with a tongue 12'? which is, adapted to engage in agroove 122 of the cutter head. The blade has an integral .stud 128adapted to pass through a slot.123..of the cutter head. :Badialadjustment of. the blade is effected by;

means of-screws 129'and 130. The screw 129 threads into the cutter headand engages the stud 128 on one side thereof. Each screw 130 threadsinto the cutter head for movement transversely thereof and is providedwith a conical inner end 131. This inner end 131 is adapted to engagethe beveled end of a pin 132 whichengages at its other end the stud 128at a point diametrically opposite to the point of engagement of thescrew 129 with the stud," It will be seen that by unthreading the screw1'29 and by threading upthe screw 130, the pin 132 will be moved toadjust the cutter bladein one direction and by reversing theseoperations, the blade can be adjusted in the opposite direction. Eachblade is secured in any adjusted position by means of the washer 134 andnut 135, the latter threading onto the stud 128.

. The idea of providing a plane surface on the blade supporting memberto seat against a plane side face of the cutter head and thereby preventtilting of the blade in its adjustment on the cutter head, is used inthe modification of the invention illustrated in Figures 15 and 17inclusive but here the supporting member is not integral with the bladebut is constructed as a separate part to which the blade is secured.designatesthe cutter head. It is provided with a plane ground side face141 and is formed with a plurality of radial T-slots 142.

Each cutting blade 143 is secured to a supporting member 144 by a screw145. The inside faces 146v of the supporting members are ground plane toseat against the side face 141 of the cutter head. The supportingmembers are, also, recessed on their inside faces as indicated at 147 toreceive the upper end of T'-blocks 148. A block 148 is secured to eachsupporting member 144 by a screw 149 an-d'a dowel pin 150. The T-blocks148 are adjustable radially of the cutter head in the T-slots 142 bymeans of a differential screw device comprising the screw 151 whichthreads into the T-bl'ock 148 at one end and into another screw 152atthe other end, the latter screw -152.threading into the cutter head.

Instead of providing a socket or slot in the periphery of eachsupporting member 144 into which to seat the cutting blade 143, it isdeemed preferable to grind the periphery of the supporting member 144 aspart of a coni- .0311 surface and grind a conical surface on the insideof the cutting blade. The conical surface on the blade is so ground,preferably, as to undercut the blade below its cutting portion', asclearly shown in Figure 17 and provide a shoulder 155 which is adaptedto seat against the upper face of the supporting member 144 when thescrew 145 is threaded home.

conical surfaces on all the supporting members simultaneously. Hencewhen the blades are assembled on the head they will all have exactly thesame pressure angle.

Figure 18 illustrates another modification of the invention in which thesupporting member is separate from the cutting blades and in which theinside face of the supporting member is ground plane to seat against aground side face of the cutter head. designates the cutter head. It isprovided with a plane side face 161 and formed with a plurality ofradial T-slots 162. Each blade 163', as before, is preferably providedwith a conical surface to-seat against a correspond ingly shaped conicalsurface 164 ground on the periphery of the supporting member165 and theshoulder 166 formed on the blade rests against the outer face of thesupporting member. Each blade is secured to its supporting member by ascrew 167. The supporting members 165 as in the'case of the supportingmembers 144 have their inside faces ground plane to seat againstthe sideface 161 of the cutter head but the supporting members 165 are formedwith integral T-shaped portions engaging in the T-slots 162 of thecutter head. .Each supporting member 165 is adjusted radially on thecutter head to adjust thecorresponding cutter blade radially of thecutter head by a screw which threads at one end into the T-shapedportion of the supporting member and at its other end into another screw169 that threads into I the cutter head. The two screws form adifferential screw device permitting of a fine adjustment. A lock-nut 170 may be provided to thread onto the screw-168 to secure it in anyadjusted position, while the bolt 172" and nut 173v assists in-securin-gthe blade in. its adjusted position. A

Figures 19 to 21 inclusive illustrate a further modification of thisinvention employing supporting members separatefrom the cutting blades.designates the cutter head. It is formed with a plane side face 181 andwith a plurality of radial grooves 182. 183 designates the cutting bladeand 184 the supporting members therefor. Here the cutting blades aresecured on the inside periphery of the supporting members instead of onthe outside periphery thereof as in previously described modifications.This serves to illustrate further the scope of this invention. Theinside-peripheral surface 186' of each supporting member is groundconically and the inside face of'each blade 183 correspondingly groundand the blades formed with shoulders adapted to seat on the outsidefaces of the supporting memhers. Each blade is secured to its supportingmember by a screw 187. The supporting members 184 have their insidefaces 188 ground plane to seat against the side face 181 of the cutterhead and are formed with i grooves189. Blocks 190 and 191 which. aresecured in the groove -182 of the cutter head by dowel pins 192 and 193-engage-' in the groove 189 of each supporting memberb184 andserveto'guide the supporting member 184 in its radial adjustment on thecutter head.

No special means has been illustrated for adjusting the supportingmembers 184 on the cutter headand it will be understood that any of themeans heretofore described or' any other suitable means may be employedfor this purpose or that the cutter truing fixture may be arranged so asto effect this adjustment. Each supporting member 184 is secured in anyadjusted position by means of a screw 195 that threads into the cutterhead 180 and a washer 196 which engages the.

supporting member. 184. Preferably, the. supporting member 184 isrecessed, as indicated at 197 to receive the head of the screw 195 andthe washer 196. Y

Figures 22 to 24 inclusive illustrate further embodiment of theinvention. Here,

' by means of a dowel pin 204. 205 designates the cutting blade and 206the supporting member to which the blade is secured by means of a screw207. The supporting member 206 is, preferably, provided with a conicalperipheral surface 208, as in the preceding embodiment, and the cuttingblade 205 is formed with a correspondingly shaped inside face adapted toseat against the peripheral face 208 and with a shoulder 209 adapted toseat on the outer face of the supporting member 206 whenthe blade issecured to the supporting member.

The supporting member has its inside face 210 ground plane to match theside face 201 of the cutter head against which it seatsand thesupporting member 206 is formed with a groove 211 in which the block 203is adaptber 206 in its'radial adjustment on the cutter head. This radialadjustment may be effected in any suitable manner; The supporting member206 is secured in any ad justed position by means of screws 212 whichpass through the supporting member, one on either side of the groove 211and thread into the cutter head 200 on either side of the tongue orblock 203. The supporting member 206 is preferably recessed as shown at215 and 216 in Figure 23 to receive the heads of the screws 212 and thewashers 217.

Other modifications of the invention are possible as will be clear tothose skilled in the art to which the invention pertains. In.

general, it may be said that the invention is capable of various furthermodifications and uses and that this application is intended tocover-any variations, uses, or adaptations of the invention following,in general, theiprinciplesof the invention and including such departuresfrom the present disclosure as come within known or customary practicein the art to which itpertains and as may be ,app'liedto theessentialfeatures hereinbefore set forth and as fall withinthe scopeofthe invention orthe limits of the appended claims. 1 Having thusdescribed my inventionnvhat Iclaim is! A ge'arucutter. comprising arotatable headhaving a radial grooveformed therein "and aradial:slot.communicatingwith said groove and. having a plane side face,a blade having a cutting portion projecting beyond the adjacent sideface of the head in thedirection of the axis of the head andv asupporting portion formed with a plane face adapted ting po rtion havinga side-cuttingedge,

"means foradjusting the'blade radially on the head and means adapted to.besecured to said stud for holding the blades in any. adjustedposition." Y Y 2. A gear cutter comprising a rotatable head having aradial groove formedtherein and a radial slot communicating with said toseat on the plane face of the head and with V a tongueengaging in saidgroove and having a stud which passes through said slot connected tosaid supporting portion, said cut-' 00.

groove and having a plane side face, a blade having a cutting portionprojecting beyond the adjacent side face ofthe head in the direction ofthe axis of the head and a sup- 7 porting portion formed with a planeinside face adapted to seat on the plane faceof the head and with atongue engaging in said groove and havinga .stud connected to saidsupporting portion which passes throv gh said slot, said cutting portionhaving. a side-cub ting edge, means engaging said stud for 3dr] justingthe blade radially on the head, and

means secured to the stud "for holding the j blade in any adjustedposition. L ed to engage to guide the supporting mem- 3. A:gear.cuttergcomprising a rotatable head having a radial groove formedtherein and. a, radial slot communicating withsaid I V groove'and havingaplane side face, a blade havinga cutting portionprojecting beyond theside face of the head in the direction of 3 a tongue'engaging in saidgroove and havinga stud connected to said supporting portion whichpassesthrough said slot, sald cuttlng portion having'a side-cuttingedge, apinengaging-said stud-having abeveled outerend,

m re-wforaadjusting the blade radially on the head, saidscrew-beingthreaded intoth'e head transversely thereofand havinga ta.-

pered noseengaging the bevelof said pin,

and means for securing the blade in any ad justed position.

4. A gear cutter comprising a rotatable head having a radial grooveformed therein and a radial slot communicating with said groove andhaving a plane side face, a blade having a cutting portion projectingbeyond the adjacent side face of the head in the direction of the axisof the head and a supporting portion formed with a plane inside faceadapted to seat on the plane face of the head and with a tongue engagingin said groove and having a stud connected to said supporting portionwhich passes through said slot, said cutting portion having aside-cutting edge, and a screw threaded into said head and engaging saidstud for adjusting the blade radially on the head. a

5. A gear cutter comprising a rotatable head having a plane side faceand formed with a plurality of radial slots, a plurality of blades, eachof which has a seating portion, the underside of which is plane and isadapted to rest against the plane side face of the head, a cuttingportion extending from said seating portion beyond the adjacent sideface of the head in the general direction of the axis of the head andhaving a side cutting edge which is inclined to the axis of'the head,and a shank-portion which engages in and passes through one of the slotsof the head, means engaging the shank-portion of each blade and movablein the head for adjusting the blade radially in the head, and means forsecuring each blade in position after adjust ment.

6. A gear cutter comprising a rotatable head having a planeside face andformed with a pluralityof radial slots, a plurality of blades, each ofwhich has a seating-portion, the underside of which is plane and-restsagainst the plane side face of the head, a cutting portion extendingfrom said seatingportion beyond the adjacent side face of the hgad andhaving a side-cutting edge inclined to the axis of the head, and acylindrical shank-portion which engages in and passes through one of theslots of the head, and means engaging the shank portion of each bladeand movable in the head for adjusting the blades radially in the head,and means for securing each blade in position after adjustment.

7. A gear cutter comprising a rotatable head having a plurality ofradial slots formed therein, a plurality of removable cutter blades,each blade having a shank-portion which passes through one of the slotsof the head, and a cutting portion, which, when the blade is in positionon the head, extends beyond the adjacent side face of the head in the drection of the axis of the head and prov ded wlth a side cutting edgewhich i i clined to the axis of the head, means for

